1. Field of the Invention
The present invention relates generally to a method of detecting a bank angle being experienced by a moving vehicle. More particularly, the present invention relates to a method for detecting the bank angle under dynamic lateral operating conditions for use in a motor vehicle yaw having a control system.
2. Disclosure Information
Automotive vehicles with braking systems which respond to vehicle conditions as well as driver input have been produced. For example, when a particular yaw rate is desired, as indicated by a driver's steering wheel operation, if the vehicle is not producing an adequate yaw rate, the braking system of the vehicle may compensate by altering a particular wheel's speed. This control is dependent on accurate measurement of several vehicle operating conditions. It had been observed that error can be introduced in the control system if the vehicle is operating at a bank angle. Therefore, it is desirable to determine the bias in the various operating condition signals introduced by operating at a bank angle.
U.S. Pat. No. 5,446,658 ('658) addresses the problem of estimating bank angles of a road surface. However, under various operating conditions, the system described in '658 patent does not have the ability to calculate the road surface bank angle under dynamic lateral operating conditions. Specifically, if the yaw rate for the vehicle changes by more than a predetermined threshold, the previously determined bank angle is assumed as the current bank angle. Of course, it is quite possible for a vehicle to undergo extreme bank angle variation during the period that the yaw rate is not within a predetermined threshold.
It would be desirable to provide a method for determining a bank angle being experienced by a motor vehicle that is robust to dynamic lateral vehicle operating conditions.